SE1550959A1 - Method and apparatus for reducing the flow of ground air to indoor air in a building - Google Patents

Abstract

The present invention relates to a method for reducing the flow of ground air to indoor air in a building (1), the building comprising at least one cradle (2), which cradle comprises a permeable channel (23) in contact with ground air, the method comprising providing a flood stop (24) for the ground air in the permeable duct (23). The invention also relates to a device for reducing the flow of ground air to indoor air in a building (1). Publication figure: Fig. 2a-c

Description

TECHNICAL FIELD The present invention relates to a method for reducing the flow of soil air to indoor air in a building. The invention also relates to a device for reducing the flow of soil air to indoor air in a building, as well as a building with a low content of soil air in indoor air and an alternative method for reducing the flow of soil air to indoor air in a building.

BACKGROUND That soil air containing harmful substances, mainly radon gas, can be sucked into buildings and remain there hereditary edge, as well as the negative effects this has on the throat of prehuman beings living in such buildings. Ground air is sucked into buildings due to a negative pressure in the building or an overpressure in the ground. Mechanical ventilation or thermal (the so-called chimney effect) rising force draws radon gas into the structure via, for example, impurities, micro-cracks in the concrete structure, and pipe penetrations.

Since radon gas is volatile and is affected by at least a small change in air pressure, the gas follows the movement of the ground air in buildings. The gas can move in some cases horizontally, but vertical rises are the most widespread gas migration, above all via micro-cracks in concrete or inaccessibility in the construction of the concrete slab. Ground air contains a number of harmful substances, of which radon is the one that is most known and has the greatest impact on human health. l0 Structures built with so-called blue aerated concrete (also edge as blue concrete) meant that radon-containing building material could varnish radon from cradles and other detailed building technical details in the construction.

An estimated 500,000 different types of housing and buildings in Sweden today have radon levels in excess of 200 Bq / m3 and radon gas currently causes about 400 deaths per year. Most of these are related to the combination of radon and smoking or passive smoking.

Since negative pressure in buildings and overpressure in soil conditions are the cause of radon levels that exceed the current spruce value of 200 Bq / m3, radon levels are often measured in buildings where radon is radiated to radon from the ground, with some form of extraction device that sucks gas under the concrete structure to the ground. blow the cape via the outer wall or via the exhaust air ventilation above the roof. If the radon gas comes from the building material (blue concrete), the solution is "doubled air turnover = half radadon content", which in practice leads to a very high heating cost to handle the air exchange and the need for heating the building.

According to the National Board of Housing, Building and Planning, there are many buildings with such high-level radon levels that it is not possible to remedy the cost per life saved with reasonable means. In these problem properties, it was said that it is radon that leaches in from the building material (blue concrete) and that the removal of these is about the conversion of carbon dioxide with mechanical ventilation. However, this has significant disadvantages, partly because heating costs for the extension increase sharply as mentioned above, and partly because it is associated with high investment costs.

There is therefore a great need for improved methods to reduce the radon content in buildings, both of neck shells and of economic shells. SUMMARY OF THE INVENTION The object of the present invention is to eliminate or at least to reduce the problems described above. This is achieved by a method and device according to appended independent claims, where the movement of air in the cradle of a single building is affected so that soil air from ground or an area of the ground is prevented from moving up inside the cradle and into the building itself.

When the ground air moves in the direction at which the pressure is at least, there is a hitherto unknown cold to elevation levels of e.g. radon in buildings. Vertical rises in outer walls and certain inner walls of older sections can in fact give rise to very high concentrations of radon buildings on all floors.

As an outer wall in its nature has the purpose of reducing heat loss or otherwise reducing the impact of the surrounding atmosphere on the climate within the climate zones, certain air movement is allowed to take place in the outer wall. With a negative pressure created in the building by the thermal rising force (naturally ventilated buildings) or by the mechanical ventilation, an air migration also takes place outside the climate zones (outer wall) into the building.

When the radon gas is allowed to migrate into the outer wall via the construction of the outer wall, the cradle is in principle similar to a radon-like lining on the ground, which can be with hogan concentrations of radon gas that move into the building via various types. The outer walls that have insulation in the outer wall where air can be sucked in via the ground give a risk that the attracted gas rises to very high levels due to the air gap that is to ensure that the façade can withstand the climate outside the building's climate zone.

When a negative pressure is established in the air gap / counter-casting / plaster surface between the building's façade and the inner 10th structure in the cradle, a vertical air movement takes place in all or parts of the cradle section until it meets an obstacle such as the rising force. The obstacle in this case is the negative pressure that buildings have due to the negative pressure created by the ventilation in the building. The air that moves in this air gap, if it is connected to land, is also contaminated by radon gas. As the radon gas is volatile, it follows the rest of the air into the buildings. The type of façade that primarily causes this problem has been installed underground and then continued up along the façade.

Apartment buildings often have problems with elevated radon levels in the upper floors. Radon levels can seem inexplicable and are often led to building materials or movements in pipelines. However, measures against this have no effect as they do not affect air movements in façade construction. Through investigations, however, the inventor has identified radon as the pearmeable air layer in façades. Furthermore, air movements can be identified where the concrete structure meets the outer wall, this is when this "bridge" of concrete enters the façade where air movements take place in connection with the outer wall material.

The insight underlying the present invention is thus that the presence of harmful substances in soil air, mainly radon, in buildings can only be partly explained by the fact that radon leaches in through bottom plate and cracks or penetrations in it. Contrary to what Langane is considered to be an established scientific truth, a significant supply of radon can thus take place through rocks, high up in a multi-storey building due to the thermal rise of air in the outer rock, and radon gas can then be explored into the building. Thanks to this insight, completely new methods and devices can be created to reduce the radon content of existing buildings and to avoid the presence of radon in newly produced buildings. By using the present invention and the insight underlying it, the radon concentration in buildings can thus be dramatically reduced, in some cases completely eliminated, which is impossible with day techniques because they are not based on the insight into how the problem actually arises. In contrast to the methods and devices already known in the field, the present invention also has a passive system, which does not involve costs in the form of increased energy consumption for preheating or constantly operating flatbed units to vent radon-containing air.

DRAWINGS The invention will now be described in more detail with reference to the accompanying drawing figures, in which Fig. 1 shows a plan view of a building in which ground air varnishes enter through floors and cradles; Fig. 2a shows a sectional view of a house wall with a recess in the facade according to a preferred embodiment of the present invention; Fig. 2b shows a sectional view of a house cradle where part of the façade in contact with ground has been removed; Fig. 2c shows a sectional view of a house wall where an object is inserted as a river stop; Fig. 3 shows a perspective view of a building with a single device according to the invention; Fig. 4 shows a sectional view from the side of a single cradle where a permeable part is located inside the cradle; Fig. 5 shows a sectional view from the side of the cradle in Fig. 4 with a preferred embodiment of an alternative method for reducing the radon concentration through the eight layers of air from the cradle; and Fig. 6 shows a sectional view of a cradle and a bottom plate of a building, where a river stop is inserted between them.

DETAILED DESCRIPTIONFig. 1 shows a building 1 with rocks 2, and a roof 4, where soil air which, among other things, can contain radon from radon-containing soil leaches in. As long as the canteen has been in the area, soil air seeps up towards the bottom plate 3 and penetrates into the building through cracks or impurities and mixes with the indoor air in the building. This is shown by dashed arrows against the bottom plate 3 in the figure. In order to reduce radon content, the accepted way, as also shown in the figure, has been to drill holes through the bottom plate 3, so-called radon suction 31, and connect them to pipelines 32 connected to a suction device 33 with a flake that blows out radon gases into the building and thereby reduces the amount of gas the building. However, this evacuation only creates a subsidence of natural gas between the outer foundation walls that act as barriers and prevents the evacuation of natural gas beyond them. "Upper" It should be noted that when terms such as "up", "down" or "lower" are used, this occurs in relation to directions which are normally up and down on a building, ie up to a roof and down to the ground on which the building stands. It should also be noted that radon has been cited as an example of harmful substances in soil air, and that the invention also used in an advantageous way to reduce the content of other substances (fuktš.

The figure also shows the second and hitherto unknown location on which radon enters the building. In the cradle 2 there is generally an inner part 21, which carries at least in some part of the cradles, and a facade 22 which is fixed to the inner part 21 and is intended to provide insulation and a water-resistant surface layer to prevent water from penetrating into the cradle 2. Often runs the façade 22 along the inner part 21 all the way down into the façade 22 the ground, so that a uniform appearance is achieved. there is also a permeable channel 23 where an air volume can move a bottom plate 30 10 itself, often in the form of an air gap but in some cases also in the form of a counter-casting or plaster surface. Radon can penetrate into the cradle from the surrounding ground and amount to the volume of air where it rises through thermal movement and can penetrate into the building genomic atoms or penetrations in the inner part 2l of the cradle 2 so that it amounts to the indoor air.

In Fig. Where the inner part 21, 2a-c are shown the cradle 2 in more detail, the facade 22 and the permeable channel 23 are visible. In Fig. 1 there was thus an air volume in the permeable channel 23 and could move freely there, but Figs. 2a-c also show different variants of a river stop 24, in order to prevent the ground air from moving up through the cradle.

In Fig. 2a, the river stop 24 in the form of a recess in the façade 22 is inhaled through the permeable channel 23 to the inner part 211. Thanks to the river stop 24, the air volume is divided into the first air volume 25 located in the permeable channel 23 on one side of the river stop 24 and a second air volume 26 located in the permeable channel 23 on the other side of the river stop 24. A river stop 24 thus prevents a connection between the first air volume 25 and that second volume of air 26, so that they are separated from each other. The second air volume 26 is located in a lower part of the façade 22 and will thus contain ground air with radon, while the pre-air volume 25 is located in an upper part of the façade 22, above the flood stop 24, and will thus be free of radon. sucked into that pre-air volume 25 to be taken from surrounding outdoor air vents from the second air volume 26.

The river stop 24 can thus be designed in many different ways, and in its simplest design is a distance between the first air volume 25 and the second air volume 26 which is sufficiently large to allow circulation of outdoor air in the recess, which distance is in the range 2 to 15 cm. In Fig. 2b, the river stop 24 is in the form of a recess where the lower part of the façade in contact with the ground has been removed. Thereby, air to the permeable channel23 will be taken from the surroundings rather than from the ground.

In Fig. 2c, the river stop 24 is in the form of an object, for example a plate or the like, which is inserted into the façade and cut by the permeable channel 23 so that the flow of soil air is prevented.

When the river stop 24 is in the form of a recess as in Fig. 2a, it is advantageous to also supply a drip strip which is mounted at the inner part 21 of the cradle 2 and runs substantially perpendicular to said inner part 21 out of the cradle 2. The drip strip 27 is fixed by fastenings and is in an outer part preferably angled downwards to prevent water from rain or snow from entering the façade 22 in that lower part. To ensure the thermal rise in the permeable channel 23 above the river stop 24, the drip strip 27 is mounted at a distance from the facade so that air can easily flow between the facade 22 and the drip strip 27 and penetrate into the permeable channel 23 to be included in the first air volume 25. This is shown in Fig. 4, with a building where a recess is made to form a river stop 24. Furthermore, a drip strip 27 has been mounted along at least two cradles 2. The river stop 24 is made substantially horizontal and without stopping, radon-containing air from the ground is prevented from curving past the river stop 24. and continue up in that vestibule volume 25 above the river stop 24. It is hereby realized that it is advantageous that river stop 24 is made along all the cradles 2 of the building 1, or at least along all the cradles 2 where the facade 22 runs breath into the ground, or at least along an entire cradle 2 from a first spirit to another spirit, but it is also possible that a reduction in the avradon content may n is reached by a river stop 24 along only a rock 22 or even a part of a rock 22.

In the case where the river stop 24 is an outcrop, the outcrop is preferably about 2-15 cm high, depending on the bearing capacity of the wall and construction at a given building site, but it is also understood that the height measured or also measured too deep feels suitable for certain construction sites depending on its special properties. Fig. 4 shows an alternative design of a wall 2 where the inner part 21 of the wall is heterogeneously formed and sufficiently porous for a permeable nozzle 23 to be found inside the inner part 21. Here, all felt goose geese penetrate into and through an interior of the wall 2 from the underlying mark, and feel it then seep into the building nets 1. To reduce the concentration of indoor air in the indoor air, a heel 41 can be created, for example by drilling from the inside of the house, from the wall 2 and into its interior, and to this heel feel the suction device 42 is closed, with a fan 43 which For example, an embodiment where ground air leaks through the insulation, which, for example, feels like herringbone slabs, i.e. is shown in Fig. 6, is shown in Fig. 6. through an area where the bottom plate 3 of the house is attached to the wall 2. The river stop 24 is cleaned there through a seal between the bottom plate 3 and the wall 2. It is to be noted that the object mentioned above with reference to an embodiment is also freely combined with other embodiments, as can be seen. the professionals.

Claims (1)

A method for reducing the flow of soil air to indoor air in a building (1), the building comprising at least a cradle (2), which cradle comprises a permeable channel (23) in contact with soil air, characterized in that the method comprises providing a river stop (24) for the ground air in the permeable duct (23). A method according to claim 1, wherein said at least one cradle (2) comprises an inner part (21) and a facade (22) mounted on the inner part, and wherein said facade comprises said permeable channel (23) and that permeabile channel contains an air volume, characterized by said river stop (24) is obtained by providing a compartment of at least a part of the facade of the cradle so that the air volume is divided into a first air volume (25) and a second air volume (26). The method of claim 2, wherein the river stop comprises a recess in the façade inhaling into the permeabile channel (23) so that a distance (d) is provided between a first part of the façade (22) comprising that pre-air volume (25) and a second part of the façade. comprising the second volume of air (26). A method according to any one of claims 1-3, wherein said river stop (24) is obtained by inserting an object which provides a compartment of the permeable channel (23). A method according to any one of claims 1-4, wherein said at least one cradle (2) comprises an inner part (21) and a single-phase (22) mounted on the inner part, and wherein said river stop (24) is obtained by removing a part of A method according to any one of claims 1-5, A method according to any one of claims 1-6, A method according to any one of claims 1-7, The method according to any one of claims 2-3, The facade which is in contact with ground. the river stop running along the cradle from a first spirit to a second spirit. wherein the flood stop runs substantially horizontally on the building (1). the building comprising four rocks and the river stop running over all four rocks. the river stop comprising a drip strip (27) as arm mounted in the cradle and arranged to protect the façade below the river stop from incident downboard. Method according to claim 1, wherein the river stop comprises a seal between the cradle and a base plate of the building. The device for reducing the flow of ground air to (1), comprises at least one cradle (23) indoor air in a building, the building (1) (2), in contact with ground air, (24) comprising the cradle comprising permeable channel characteristic of a river stop (23). ) in the permeable duct to reduce the flow of soil air. wherein said (21) device according to claim 11, at least one cradle (2) comprises an inner part and a facade (22) mounted on the inner part, and wherein said facade comprises the permeable channel and said 13. 14. 15. 16. Permeable duct contains an air volume, characterized in that the river stop (23) comprises a compartment of at least a part of the façade so that the air volume is divided into a first air volume (25) and a second air volume (26). The device according to claim 11 or 12, the river stop comprising a recess in the façade (23) through the permeable channel so as to provide a distance between a first part of the permeable channel comprising the first air volume (25) and a second part of the permeable duct comprising the second volume of air (26). A device according to any one of claims 11-13, wherein said river stop (24) is obtained by inserting objects to provide a section of the permeabile channel (23). (21) A device according to any one of claims 11-14, said at least one cradle ( 2) comprises an inner part and a façade (22) mounted on the inner part, and said river stop is obtained by removing a part of the façade which is in contact with ground. Device according to any one of claims 11-15, wherein the river stop comprises a drip strip (27) as mounted in the cradle and arranged to be arranged to protect the facade below the river stop from incident downboard. Device according to claim 16, wherein the drip strip is formed with a drip protection part integrated or is movable in relation to the drip strip and can be attached to it. A device according to any one of claims 11-17, wherein the river stop is integrated with the façade. A device according to any one of claims 11-18, wherein the river stop comprises a seal between the cradle and a base plate of the building. A building comprising at least one cradle with a device according to any one of claims 11-19. Method for reducing the flow of soil air to (1), with an inner part (23) wherein the building comprises (21) as indoor air in a building at least one cradle (2) comprises a permeable area where an air volume can be characterized in that the method comprises (41) can move, create a hole from one side of the cradle and into it (23), and where the method further comprises (42) permeable areas for operatively connecting a suction device to said cradle so that a negative pressure is created in the cradle. Device for reducing the flow of ground air to indoor air in a building (1), comprising at least one wall (2) with an inner part (21) comprising a (23) with an air volume can move, (41) permeable area pitcher characterized by a hole which runs from a surface of the cradle and into the permeable area, and further comprising a suction device (42) connected to said hole so that a negative pressure is created in the cradle.